Analog Devices Inc./Maxim Integrated MAX9933EUA+T

Overview

MAX9933EUA+T from Maxim Integrated is a 2MHz–1.6GHz RF logarithmic detector IC designed for transmitter power measurement and RSSI in wireless terminal devices. It delivers 45dB dynamic range, -58dBV to -13dBV input voltage range (equivalent to -45dBm to 0dBm at 50Ω), and linear-in-dB response with 25–27mV/dB slope across frequency. Its 8-pin μMAX package supports compact RF front-end integration.

For engineers reviewing the MAX9933EUA+T datasheet, MAX9933EUA+T pinout, MAX9933EUA+T application, or MAX9933EUA+T equivalent, this page provides verified specifications, functional pin definitions, real-world use cases in GPON-CATV triplexors and cellular handsets, and validated alternative parts for RF power detection design.

Technical Context

The MAX9933EUA+T implements a five-stage logarithmic amplifier strip with 10dB-per-stage gain and full-wave rectification per stage, enabling precise RF power-to-voltage conversion. Its output is buffered and delivered directly to OUT, eliminating external op-amp requirements for ADC interfacing.

Unlike controller variants (MAX9930–MAX9932), the MAX9933EUA+T lacks SET input and is optimized solely as a detector-its OUT voltage directly encodes input RF power level via logarithmic transfer function: RFIN = (OUT / SLOPE) + IP, where typical SLOPE = 25.5mV/dB and IP ≈ -56dBm at 2MHz/25°C.

Key Specifications

Pinout & Package

The MAX9933EUA+T is housed in an 8-pin μMAX® package (3mm × 3mm, 0.8mm height), RoHS-compliant and lead(Pb)-free (+T suffix). Pin 1 is marked with a dot; pin numbering follows standard counter-clockwise orientation from top-left corner.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar RF detector applications.

Compared with LT5537 and AD8313, the MAX9933EUA+T offers tighter temperature drift (±0.5dB vs. ±1.0dB), lower shutdown current (13μA vs. 20–50μA), and optimized 2–1600MHz performance for cost-sensitive consumer RF front-ends.

Availability

MAX9933EUA+T is available at Aetrix Electronics and suitable for GPON-CATV triplexors, cellular handset RF front-ends, and wireless terminal device TSI monitoring requiring stable component supply across industrial temperature ranges.

Supply support for MAX9933EUA+T includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Maxim Integrated, now part of Analog Devices, designs precision analog, mixed-signal, and RF ICs for communications, computing, and industrial applications.

The MAX9930–MAX9933 family was developed specifically for RF power detection and closed-loop PA control in wireless infrastructure and consumer terminals, emphasizing logarithmic accuracy, temperature stability, and minimal external component count.

FAQ

What is the primary function of the MAX9933EUA+T?

The MAX9933EUA+T is a dedicated RF logarithmic detector IC that converts RF input power (–45dBm to 0dBm) into a proportional DC output voltage (0.36V to 1.45V) with 45dB dynamic range and ±1dB linearity. Unlike controller variants (MAX9930–MAX9932), it has no SET input and is used exclusively for measurement-not closed-loop control-making it ideal for RSSI and TSI applications where the output feeds an ADC in a baseband processor.

Does the MAX9933EUA+T require external components for basic operation?

Yes, the MAX9933EUA+T requires three external components for functional operation: a 0.1μF ceramic bypass capacitor between VCC and GND, an AC-coupling capacitor in series with RFIN, and a capacitor (typically 150pF) between CLPF and GND to set detector bandwidth. No external resistors or DACs are needed, distinguishing it from controller variants like the MAX9930EUA+T which require a SET voltage source.

What is the significance of the CLPF pin on the MAX9933EUA+T?

The CLPF pin on the MAX9933EUA+T connects to an external capacitor that sets the small-signal bandwidth (4.5MHz typical with 150pF) and filters high-frequency noise from the logarithmic output. This capacitor directly determines the detector's response time and averaging behavior-critical for RSSI stability in burst-mode transmissions. Unlike the SET pin on controller variants, CLPF does not affect setpoint or control logic; it solely shapes the analog output filter response.

How does the MAX9933EUA+T handle temperature variation in RF power measurement?

The MAX9933EUA+T maintains ±0.5dB log conformance error over its full –40°C to +85°C operating range, as verified in Typical Operating Characteristics plots. This stability is achieved through on-chip temperature compensation of the logarithmic slope and intercept, eliminating the need for system-level calibration in outdoor GPON nodes or mobile handsets. The error remains bounded even at extreme temperatures and across the full 45dB dynamic range.

Can the MAX9933EUA+T be used in place of the MAX9930EUA+T in a PA control loop?

No-the MAX9933EUA+T cannot replace the MAX9930EUA+T in a closed-loop PA control application because it lacks the SET input required to define the target output power level. The MAX9930EUA+T uses SET to establish a reference voltage that the OUT pin drives toward; the MAX9933EUA+T outputs only a raw log-detected voltage. Substituting it would break the control loop unless the baseband IC implements full digital control using the MAX9933EUA+T's output as feedback.